Study on crack dynamic evolution and damage-fracture mechanism of rock with pre-existing cracks based on acoustic emission location

作者：Yuanyuan Wang, Hucheng Deng, Yong Deng, Kangping Chen, Jianhua He · 发表于：Journal of Petroleum Science and Engineering · 年份：2021 · DOI：10.1016/j.petrol.2021.108420 · 被引用次数：117 · 研究领域：Rock Mechanics and Modeling、Geotechnical and Geomechanical Engineering、Landslides and related hazards

The acoustic emission (AE) location technique is used to characterize the entire progressive failure process of rock with preexisting cracks. The mechanical properties, AE characteristics, crack dynamic propagation process, failure modes and damage-fracture evolution rules are studied for prefabricated rock samples with different crack inclination angles under uniaxial compression. The results show that the peak strength and elastic modulus first decrease and then increase with increasing crack angle. AE events exhibit different characteristics with changes in stress. In the initial compaction and elastic deformation stage, the AE activity is not obvious; when microcracks form in the rock sample, the AE count increases; after entering the crack stable growth stage, the AE activity becomes significant; during the period of unstable crack propagation to rock failure, the AE activity is extremely active. The AE location can well accurately reflect the crack initiation position, propagation direction and surface orientation in the rock. AE location can well reflect cracks initiation position, propagation direction and space surface shape in the rock. For intact samples, microcracks are first generated at the ends of the sample and extend internally along the loading direction until they coalesce and form macroscopic cracks; for precracked samples, microcracks appear first at the tips of the prefabricated crack, and extend outward at a certain angle, while the microcracks are main...